The Chemistry of Low‐Valent Organoaluminum Species

Abstract

During the past 25 plus years, room‐temperature stable aluminum(I) and (II) compounds have become available through standard organometallic techniques, and their reactivity has been explored in much detail. The chemistry of aluminum(I) compounds may be viewed as that of a very reactive carbene (singlet and triplet, depending on the substrate). Typical reactions involve insertions into various EE or EX bonds and adduct formation with Lewis acids. Aluminum(II) compounds are generally dialumenes (R2AlAlR2) featuring an AlAl single bond. Their chemistry is similar to that of alanes (R3Al) with respect to substitutions and Lewis acid base chemistry but with a strong redox component. In many cases, substrates insert into the AlAl bond in a formally oxidative manner.

Alkylaluminum Complexes as Precatalysts in Hydroboration of Nitriles and Carbodiimides

“…Entering the 21st century, more and more chemists have come to the consensus that main group compounds can imitate the behavior of transition metal complexes. − Organoaluminum compounds are favored as excellent nucleophiles for organic reactions because of the high Lewis acidity of the aluminum center, high reactivities, low prices, and low toxicities. These advantages have encouraged scientists to develop new organoaluminum derivatives to catalyze a wide variety of chemical reactions. − In 2015 we reported on an aluminum-hydride that catalyzed hydroboration of compounds with unsaturated bonds. , Since then, the research on catalytic properties of organoaluminum compounds has been developing rapidly. − However, the study of organoaluminum catalyzed hydroboration of nitrile is still in its infancy, , and organoaluminum catalyzed hydroboration of carbodiimide has not been reported yet. Therefore, the development and research of aluminum catalysts for these two kinds of reactions is very important.…”